David Joshua Peterson (born January 20, 1981) is an American conlanger, writer, and artist, who has constructed languages for television and movies such as Thor: The Dark World and Doctor Strange as well as the Dothraki and Valyrian languages for the television series Game of Thrones. 
Peterson has worked to popularize the activity of language creation, or "conlanging". He produced a number of videos on YouTube, in a series called The Art of Language Invention, and published a book of the same title in 2015. Peterson also worked as an executive producer on the 2017 documentary film, Conlanging: The Art of Crafting Tongues.